Dishwashing apparatus



Nov. 15,1966 A w. DUNHAM DISHWASHING APPARATUS 4 Sheets-Sheet 1 FiledNov. 17, 1964 INVENH'OR ANSEL W. DUNHAM Filed Nov. 1.7, 1964 4Sheets-Sheet 2 FIGS.

INVENTOR A NSEL W. DUNHAM ATTYS Nov. 15, 1966 A. w. DUNHAM DISHWASHINGAPPARATUS 4 Sheets-Sheet 5 Filed Nov. 17, 1964 ATTYS Nov. 15, 1966 A. w.DUNHAM 3,

DISHWASHING APPARATUS Filed Nov. 17, 1964 4 Sheets-S eet 4 FIGS.

INVENTOR ANSEL W. DUNHAM ATTYS.

United States Patent "ice 3,235,779 DISHWASHING APPARATUS Ansel W.Dunham, Napa, Calih, assignor to King Fifth Wheel Company, Mountaintop,Pa., a corporation of Pennsylvania Filed Nov. 17, 1964, Ser. No. 411,7414 Claims. (Cl. 134-44) The present invention relates to dish washing,and more particularly to commercial dish washing of the type wherein thedishes and other tableware are placed in trays which are put through adish washing cycle of a relatively short time period. More specifically,the present invention constitutes an improvement upon the inventiondisclosed in my earlier Patent Number 2,307,363, issued January 5, 1943.

A primary object of the present'invention is to provide an improveddishwasher of the stated type wherein the dish washing cycle is reducedin time to a minimum and yet which is fully elfective to cleanse thetableware both from grease and from food particles which may be ad heredthereto.

More specifically, the present invention provides a dishwasher in whichthe wash water is cascaded over the tableware in a concentrated sheetwhich traverses the entire cross sectional area of the dishwasher.

The present invention also provides a dishwasher wherein the rinse wateris sprayed over the tableware from above as well as below. and whereinthe proportion of rinse water between the overhead and underneath spraysis automatically varied in accordance with the type of the tablewarebeing rinsed.

The present invention provides an improved dishwasher which operatesefliciently and effectively to thoroughly cleanse the tableware washedtherein in a minimum length of time and with a minimum expenditure ofpower, avoiding the necessity for high pressure pumps for pressurizingthe water used.

All of the objects of the invention are more fully set forth hereinafterwith reference to the accompanying drawings wherein:

FIG. 1 is a view in side elevation with portions broken awayillustrating a dishwasher made in accordance with the present invention;

FIG. 2 is an end view of the dishwasher shown in FIG. 1

3,285,779 Patented Nov. 1 5, 1966.

bowls, serving dishes, silverware and the like, and the third form maybe used for loading tumblers, and similar glassware. Such trays are ofstandardized outer dimensions to be used interchangeably in thedishwasher, the only difference being in the arrangement of partitionsand tableware supports to accommodate the different forms of tableware.

In the operation of the dishwasher, the tableware in the tray 18 issubjected to opposing streams of wash water from above and belowrespectively. In accordance with the invention, the upper stream takesthe form of a sheet of cascading water extending substantially theentire length of the tank andtraversing from side to side therein duringthe wash cycle. The lower stream is ejected upwardly from a pair ofrotating fountain heads mounted in the bottom of the tank. The washwater is recirculated for a period of approximately 40 seconds, thewater being maintained at a temperature of approximately 165 F. bysuitable heating means in the bottom of the tank. Following the washperiod, the circulation of water is interrupted and the tableware in thedishwasher is rinsed by pairs of with portions broken away to illustratethe interior construction thereof;

FIG. 3 is an enlarged vertical cross section through the machine takenon the line 3--3 of FIG. 1 and showing the flow of wash water in thewashing period of the cycle.

FIG. 4 is an enlarged horizontal section taken on the line 44 of FIG. 1;

FIG. 5 is a fragmentary vertical sectional view taken on the line 55 ofFIG. 1 and showing the flow of rinse water in the rinsing period of thecycle.

FIG. 6 is an enlarged sectional view taken on the line 66 of FIG. 5; and

FIG. 7 is an enlarged sectional view taken on the line 7--7 of FIG. 4showing the mechanism for causing the sheet of cascading water totraverse the tank.

Referring now to the drawings, the dishwasher illustrated thereincomprises an exterior casing 10, mounting therein an interior tank 11and having a cooperating lid 12 hinged thereto as indicated at 13 (seeFIG. 2). The interior tank 11 is generally rectangular in outline andhas midway on its side and end walls inwardly projecting brackets 17 forreceiving the conventional dishwasher tray 18 into which is loaded thetableware to be washed. The tray 18 may take several forms; for example,one form may be used for loading flat plates, sauce dishes, saucers, andthe like. Another form may be used for loading cups,

opposed upper and lower rotating spray arms for a period of from 10 to20 seconds. The spray arms have outlets directed toward the middle ofthe tank to provide a spray of rinse water which serves to thoroughlyrinse the tableware. When rinsing glassware, cups, silverware, etc., thenormal distribution equally divides the rinse water between the upperand lower sprays respectively. However, when washing dishes and otherflatware which projects substantially above the bottom of the tray,means is provided to automatically increase the proportion of flowthrough the upper sprays to approximately 80%, whereby the bulk of therinse water is sprayed downwardly over the dishes and the like in thetray. When the rinse period is completed, the flow through the rinsespray is interrupted and the lid may be opened for removal of the trayof washed tableware and insertion of a tray of dirty tableware.

Referring again to the drawings, the tank is provided with a wash waterinlet 21 controlled by a suitable valve 20 and, if desired, is equippedwith a detergent dispenser (not shown), operable to inject a charge ofdetergent into the wash water during each cycle. The quantity of washwater is maintained below the level of the tray 18 by an overflow pipe26 projecting upwardly into the tank as shown in FIGS. 1 and 4. A drainis provided at 22. The wash water may be introduced into the tank atstandard line pressure and a thermostaticallycontrolled heating element23 is provided adjacent the bottom of'the tank to heat the wash water tothe desired temperature. In the present instance, as shown in FIGS. 3and 4, the heater 23 comprises a heating loop 24 and a thermostat 25projecting into the tank from its rear wall. The wash water iscirculated by means of an impeller 31 driven by a motor 33 under thebottom of the tank and having a shaft 32 projecting upwardly through thebottom of the tank centrally thereof. The impeller 31 is housed in ahollow cylindrical housing 34 open at its bottom to the tank 11 and openat the top to a manifold 35. The manifold 35 is provided with a pair ofoppositely directed passageways 36 and 37 connected at their freeextremities to openings 38 and 39 in the side wall of the tank. Ducts 40and 41 are connected to the openings 38 and 39 and diverge upwardly toconnect with orifices 42 and 43 which extend along the length of thetank 11 adjacent its upper end. Thus, as shown by the arrows in FIG. 3,the wash water is impelled upwardly through the passages 36 and 37 andducts 40 and 41 to provide a stream of wash water which cascadesoutwardly through the orifices 42 and 43 over the tableware in the tray18. As indicated, the streams, indicated by the arrows at 44 and 45,meet and cascade downwardly in a sheet 46 extending the full length ofthe side walls of the tank.

In accordance with the invention, in order to cause the sheet 46 totraverse across the width of the tank, flow control or baffie means isprovided. In the present instance, the baflle means comprisesproportioning dampers 48 and 49 in the passageways 36 and 37respectively. The dampers are interconnected so that when one providesmaximum flow, the other provides minimum flow and vice versa. Thus, whenthe dampers are adjusted between their opposite limit positions, thesheet 46 of cascading water resulting from the merger of the two streams44 and 45, traverses from one side of the tank to the other. In order toadjust the dampers 48 and 49 (see FIGS. 4 and 7), the dampers areprovided with arms 52 and 53 operable to engage abutments 54 and 55mounted on a slide 56 which is slidably mounted on the bottom of themanifold, for example by a .guide 57, for reciprocatory movement. Theslide is reciprocated by an arm 58 mounted at one end on the slide 56and mounted at the other end on a crank pin 59 on a control motor 60, orequivalent drive means. Thus, as the motor 60 rotates the pin 59 theslide 56 is displaced in its guide 57 from one side to the other andback. With reference to FIG. 7, rightward movement of the slide 56 andabutment 54 displaces the arm 52 counterclockwise thereby graduallyrotating the damper 48 counterclockwise against the flow of waterthrough the passageway 36, reducing the flow therethrough. In addition,displacement of the slide 56 and abutment 55 to the right permits thewater pressure in the passageway 37 to rotate the damper 49 counter-.clockwise thereby opening the passageway 37 and increasing the flowtherethrough. Thus, rightward movement of the slide 56 alters theproportion of flow so as to cause the sheet 46 to travel from right toleft as seen in FIG. 3. Thereafter, leftward movement of the slide 56restores the proportion of flow so as to cause the sheet 46 to travelfrom left to right.

Thus, as the control motor 60 rotates the crank pin 59, the sheet 46 ofcascading water traverses back and forth between the opposite side wallsof the tank. In this manner, the tableware in the tray 18 is fullysubjected to a downwardly cascading sheet of wash water. The tablewareis also subjected to upwardly-directed revolving streams of wash waterfrom fountain heads 71 and 72 rotatably mounted on the manifold 35adjacent the opposite end of the tank. The water from the manifold isdirected through the hollow fountain heads 71 and 72, and throughupwardly directed openings therein as best shown in FIG. 5. The washwater from the manifold streams upwardly through the ports 73 and 74 inthe heads 71 and 72 to provide concentrated streams of wash water toimpinge against the undersurface of the tableware in the tray 18. Thefountain heads 71 and 72 are rotated by the discharge of water throughapertures 75 and 76 in one of the arms of the fountain head. Thedischarge of water from the apertures 75 and 76 causes the fountainheads 71 and 72 to rotate in a clockwise direction as indicated by thearrows 71a and 7211. Thus, the under-portion of the tableware in thetray 18 is thoroughly washed by revolving streams of upwardly directedwash water from the rotating fountain heads. In this way, the tablewareis subjected to heavily concentrated streams both from above and frombelow to thoroughly cleanse food particles and the like therefrom.

Following a wash period of sufficient duration to cleanse the tableware,in the present instance 40 seconds, the rinse water is sprayed over thetableware. To this end, rinse arms are provided above and below the tray18. As shown in FIG. 4, the lower rinse arms are designated 81 and 82,and as shown in FIG. 1, the upper rinse arms are designated 83 and 84.The rinse arms are identical in construction and only one will bedescribed, in the present instance, the arm 82. As shown in FIG. 5, thearm 82 is hollow and has a series of orifices 85 disposed along itslength in the upper surface thereof. At each end, the arm is providedwith a nozzle 86 which operates when rinse water is expelledtherethrough to effect clockwise rotation of the arm (see FIG. 4). Thearm is mounted on a hollow tubular shaft 87 having a series of aperturesin registry with the hollow center of the arm so that as the arm rotateson the shaft, water from the hollow bore thereof is introduced into thearm from which it is sprayed through the orifices '85 and nozzles 86.The hollow shaft 87 connects at its lower extremity to a valve housing88 having a valve element 89 therein (see FIG. 6) with a stem 90 passingupwardly through the shaft 87 to project above the rinse head 82 asshown in FIG. 5. A similar hollow shaft 91 is provided for the rinse arm81 which is closed at its upper end and is connected at its lower end toa conduit 92 connected to the valve housing 88 as shown in FIG. 6. RinseWater is supplied to the housing 88 by a rinse water supply duct 95. Thehollow shafts for the spray arms 83 and 84 in the lid 12 of the tank areconnected through conduits 93 and 94 (see FIGS. 1 and 2) to the rinsewater supply duct 95 below the latters connection to the valve housing88. At its opposite end, the supply conduit 95 is connected to a rinsetank 96 having a thermostatically-controlled heating element 97 thereinand being connected to a fresh water supply line 98 having a controlvalve 99 therein.

In the operation of the dishwasher, after the completion of the washperiod, the valve 99 is opened, placing the rinse tank 96 under linewater pressure. The water pressure causes the heated rinse water to flowthrough the conduit 95 and from there to the upper rinse arms 83 and 84through the conduit 94 and into the valve casing 88. The water pressurecauses the valve element 89 to lift from its illustrated full lineposition in FIG. 6 to the broken line position, thereby affording flowof the rinsewater into the rinse arms 81 and 82 through the conduit 92and the hollow shaft 87 respectively. Under these conditions, the rinsewater is approximately equally divided between the upper rinse arms andthe lower rinse arms so that half of the rinse water is dischargedthrough the rinse arms 81 and 82 and the other half through the rinsearms 83 and 84. This is desirable when rinsing cups, flatware, and thelike.

In accordance with the invention, means is provided to automaticallyreduce the proportion of the rinse water flowing through the lower rinsearms 81 and 82 when rinsing dishes. To this end, the dish racks whichare used when washing plates and the like are provided with controlelements or clips 118 positioned to register with the valve stem 90 whenthe plate rack 18 is placed on the brackets 17 facing either direction.One of the clips 118 thereby displaces the valve stem 90 downwardlyagainst the pressure of the water in the casing 88 to the full lineposition of FIG. 6. In this position, the valve element 89 limits thewater fiow into the casing such that only approximately 20% of the rinsewater is sprayed through the lower rinse arms 81 and 82, the remaining80% being sprayed through the upper rinse arms 83 and 84. In this way,in situations where upwardly directed rinse water is not required, andit is desired to have substantialflow of rinse water in the upperreaches of the tank, the bulk of the rinsing is accomplished bydownwardly directed sprays from the upper rinse arms. A rinse period offrom 10 to 20 seconds has been found sufficient to thoroughly rinse thetableware in the tray 18, after which the valve 99 is closed, whereuponthe lid of the dishwasher may be opened and the tray removed to completethe entire cycle. In order to prevent leakage from the dishwasher duringthe wash and rinse periods of the cycle, the lid 12 is tightly fitted onthe tank 14. To accommodate the expansion of air when the temperature inthe tank is raised, a suitable vent 114 and shield 115 (see FIGS. 1 and4) is provided in the front wall alongside the upwardly divergent duct40. Additional vents may be provided for installations where theexpansion will be especially violent, for example when the washer cycleis .to be initiated after prolonged idle periods, when the unit is quitechilled.

The controls which sequentially operate the wash water inlet valve 20,the impeller motor 33, control motor 60, and the rinse water inlet valve99, may be of conventional construction. Normally, the wash water in thetank maintains the proper washing temperature through the addition ofthe heated rinse water at the end of each wash period, and the rinsetank is normally heated to the desired level during the wash period.However, when starting with cold water, suitable controls delay theoperation until the proper temperatures are attained.

It should be noted that the wash water remains in the tank at a levelbelow the tray 18, over several cycles and is drained by removing theoverflow pipe 26 from the drain opening 22 onlywhen the wash water isoverly dirty, or when the machine will be shut down for a prolongedperiod. This efi'ects a considerable saving of wash water, in that theonly water lost during each cycle is the amount used during the rinseportion which is discharged through the overflow 26, along with anygarbage particles which may float on the surface of the wash water.

While a particular embodiment of the present invention has been hereinillustrated and described, it is not intended to limit the invention tosuch disclosures, but changes and modifications may be made therein andthereto within the scope of the following claims:

I claim:

1. In a dishwasher having a tank having coextensive orifices in oppositeside walls adjacent the top and disposed along the length thereof, meansin said tank to support a rack for tableware therein below saidorifices, a manifold, impeller means operable to circulate wash waterfrom the bottom of said tank into said manifold, duct means connectingsaid manifold to each of said orifices whereby upon operation of saidimpeller means said wash water is expelled from said orifices inconfronting streams coextensive with said orifices, said streams mergingalong a line into a cascading sheet of wash water intermediate saidopposite side walls, flow control means to determine the line of mergerof said streams, and actuating means for said flow control means tocause said line of merger and therefore said cascading sheet to traversethe space intermediate said side walls; the improvement wherein saidflow control means comprises baffles mounted to intercept the flow fromsaid impeller and through said orifices, one battle for each side wall,means interconnecting said bafiles for countermovement, and drive meansto catuate said baflles to cause said cascading sheet to traverse backand forth between said opposite side walls.

2. A dishwasher according to claim 1 wherein said manifold is providedwith two outlet passageways, one for each orifice, said duct meanscomprise separate ducts, and said bafiles are pivotally mounted in saidmanifold outlet passageways to vary the flow through the associatedorifice between a minimum and a maximum, the connection providingminimum flow through one orifice concurrently with maximum flow throughthe other.

3. In dishwashing apparatus comprising a tank and means to circulatewash water through said tank in streams to wash the tableware therein,spray means for spraying rinse water over the tableware, said spraymeans comprising upper and lower spray arms disposed respectively aboveand below the tableware in the tank, a common supply for said rinsewater, separate conduits from said supply to said upper and lower sprayarms respectively, a proportioning valve connected to said supply and Ioperable to vary the proportional flow between said upper and lowerspray arms, and an operator for said valve to vary the proportional flowwhen the character of the tableware being washed and rinsed is changed,a plurality of trays for tableware; the improvement wherein at least onetray has a control element thereon, said apparatus including means tosupport each of said plurality of trays in said tank intermediate saidupper and lower spray arms, said operator for the valve being positionedfor registry with said control element of said one tray whereby uponengagament of said one tray on said support means, said control elementactuates said operator to operate the valve to thereby change theproportional flow.

4. Dishwashing apparatus according to claim 3 wherein said valvecomprises a valve casing in said supply conduit for the lower spray arm,a valve element in said casing operable in one limit position to aflordmaximum flow therethrough and operable in the other limit position toafford minimum flow therethrough, said operator comprising a valve stemconnected to said valve element and displaceable by said control elementto position said element in one of said limit positions.

References Cited by the Examiner UNITED STATES PATENTS 821,250 5/1906Miller 134-176 X 1,023,630 4/ 1912 Elkins 134-44 2,236,791 4/ 1941Forsberg 134183 2,307,363 l/ 1943 Dunham 13499 2,597,359 5/1952 McDonaldet a1 13457 FOREIGN PATENTS 104,057 3/ 1924 Switzerland.

References Cited by the Applicant UNITED STATES PATENTS 1,6-24,3 81 4/1927 Barker. 2,307,363 1/ 1943 Dunham. 2,563,109 8/ 1951 Franklin.2,597,359 5/ 1952 McDonald. 2,608,981 9/1952 Jackson. 2,824,648 2/ 8Bear. 3,101,728 8/ 1963 Broge.

CHARLES A. WILLMUTH, Primwry Examiner.

R. L. BLEUTGE, Assistant Examiner.

1. IN A DISHWASHER HAVING A TANK HAVING COEXTENSIVE ORIFICES IN OPPOSITESIDE WALLS ADJACENT THE TOP AND DISPOSED ALONG THE LENGTH THEREOF, MEANSIN SAID TANK TO SUPPORT A RACK FOR TABLEWARE THEREIN BELOW SAIDORIFICES, A MANIFOLD, IMPELLER MEANS OPERABLE TO CIRCULATE WASH WATERFROM THE BOTTOM OF SAID TANK INTO SAID MANIFOLD, DUCT MEANS CONNECTINGSAID MANIFOLD TO EACH OF SAID ORIFICES WHEREBY UPON OPERATION OF SAIDIMPELLER MEANS SAID WASH WATER IS EXPELLED FROM SAID ORIFICES INCONFRONTING STREAMS COEXTENSIVE WITH SAID ORIFICES, SAID STREAMS MERGINGALONG A LINE INTO A CASCADING SHEET OF WASH WATER INTERMEDIATE SAIDOPPOSITE SIDE WALLS, FLOW CONTOL MEANS TO DETERMINE THE LINE OF MERGEROF SAID STREAMS, AND ACTUATING MEANS FOR SAID CONTROL MEANS TO CAUSELINE OF MERGER AND THEREFORE SAID CASCADING SHEET TO TRAVERSE THE SPACEINTERMEDIATE SAID SIDE WALLS; THE IMPROVEMENT WHREREIN SAID FLOW CONTROLMEANS COM-